Signal Classification: Interactive Learning Quizzes for Electrical Engineering Students

Question 1

A signal is discrete if its:

Accepted Answer

Values are defined at specific points in time

Answer

Values can take on any value within a range

Answer

Values are continuous over time

Answer

Values are periodic

Question 2

The fundamental period of a periodic signal is:

Accepted Answer

The shortest time interval for which the signal repeats itself

Answer

The longest time interval for which the signal repeats itself

Answer

The average value of the signal over one period

Answer

The maximum value of the signal over one period

Question 3

The Fourier transform of a signal provides:

Accepted Answer

Frequency-domain representation of the signal

Answer

Time-domain representation of the signal

Answer

Phase-domain representation of the signal

Answer

Magnitude-domain representation of the signal

Question 4

Which of the following is a characteristic of a random signal?

Accepted Answer

Its values are unpredictable

Answer

Its values follow a specific pattern

Answer

Its values are constant over time

Answer

Its values are periodic

Question 5

Which of the following is an example of a continuous-time signal?

Accepted Answer

An electrical waveform representing a voice recording (continuous-time)

Answer

A digital audio signal sampled at 44.1 kHz (discrete-time)

Answer

An image represented as a collection of pixels (discrete-time)

Answer

A text message encoded using ASCII (discrete-time)

Question 6

A signal that repeats itself at regular intervals is known as a:

Accepted Answer

Periodic signal (repeats regularly)

Answer

Analog signal (not related to periodicity)

Answer

Digital signal (not related to periodicity)

Answer

Aperiodic signal (repeats irregularly)

Question 7

Which of the following is NOT a property used to classify signals?

Accepted Answer

File format (not a signal property)

Answer

Amplitude (a signal property)

Answer

Frequency (a signal property)

Answer

Power (a signal property)

Question 8

A signal that can take on only discrete values is called a:

Accepted Answer

Digital signal (can take on discrete values)

Answer

Analog signal (can take on continuous values)

Answer

Continuous-time signal (not related to value type)

Answer

Periodic signal (not related to value type)

Question 9

Which of the following is an example of a periodic signal with a period of 2 seconds?

Accepted Answer

A square wave with a frequency of 0.5 Hz (period = 2 seconds)

Answer

A sine wave with a frequency of 1 Hz (period = 1 second)

Answer

A triangular wave with a frequency of 2 Hz (period = 0.5 seconds)

Answer

A random noise signal (not periodic)

Question 10

A signal that is not periodic and has no repeating pattern is called a:

Accepted Answer

Aperiodic signal (does not repeat regularly)

Answer

Analog signal (not related to periodicity)

Answer

Digital signal (not related to periodicity)

Answer

Periodic signal (repeats regularly)

Question 11

Which of the following is NOT a type of deterministic signal?

Accepted Answer

Random signal (not deterministic)

Answer

Periodic signal (deterministic)

Answer

Aperiodic signal (deterministic)

Answer

Sinusoidal signal (deterministic)

Question 12

A signal that is generated by a physical process is called a:

Accepted Answer

Natural signal (created by nature)

Answer

Artificial signal (created artificially)

Answer

Periodic signal (not related to origin)

Answer

Aperiodic signal (not related to origin)

Question 13

Which of the following is **NOT** a property commonly used to classify signals?

Accepted Answer

Entropy

Answer

Amplitude

Answer

Frequency

Answer

Time dependence

Question 14

A signal that is defined for all values of time, i.e., it exists at all time instants, is known as a:

Accepted Answer

Continuous-time signal

Answer

Discrete-time signal

Answer

Analog signal

Answer

Digital signal

Question 15

Which of the following signals **does not** exhibit periodicity?

Accepted Answer

White noise

Answer

Sine wave

Answer

Cosine wave

Answer

Square wave

Question 16

An analog signal is characterized by:

Accepted Answer

Continuous amplitude values

Answer

Discrete amplitude values

Answer

Finite duration

Answer

Periodic behavior

Question 17

The Fourier transform of a periodic signal is also:

Accepted Answer

Periodic

Answer

Aperiodic

Answer

Discrete

Answer

Continuous

Question 18

The energy of a signal can be calculated by:

Accepted Answer

Integrating the square of its amplitude over time

Answer

Summing its values

Answer

Averaging its values

Answer

Finding the maximum of its values

Question 19

Which of the following is a property of a causal signal?

Accepted Answer

It exists only for non-negative time

Answer

It has a finite duration

Answer

It is periodic

Answer

It is non-negative

Question 20

The sampling theorem states that to accurately reconstruct a continuous-time signal from its sampled values, the sampling frequency should be:

Accepted Answer

At least twice the highest frequency component in the signal

Answer

At least half the highest frequency component in the signal

Answer

Four times the highest frequency component in the signal

Answer

Less than the highest frequency component in the signal

Question 21

Which of the following signals is considered random?

Accepted Answer

A signal with an unpredictable pattern

Answer

A signal with a predictable pattern

Answer

A signal with a periodic pattern

Answer

A signal with a finite duration

Question 22

Classify the signal x(t) = 10cos(2πt) + 5sin(4πt).

Accepted Answer

Analog, continuous-time, periodic

Answer

Digital, continuous-time, periodic

Answer

Analog, discrete-time, periodic

Answer

Digital, discrete-time, periodic

Question 23

Classify the signal x(t) = t + sin(t).

Accepted Answer

Analog, continuous-time, aperiodic

Answer

Analog, continuous-time, periodic

Answer

Digital, continuous-time, aperiodic

Answer

Digital, continuous-time, periodic

Question 24

Identify the key difference between analog and digital signals.

Accepted Answer

Analog signals are continuous in amplitude, while digital signals are discrete in amplitude.

Answer

Digital signals are continuous in amplitude, while analog signals are discrete in amplitude.

Answer

Analog signals can represent a continuous range of frequencies, while digital signals can only represent a discrete set of frequencies.

Answer

Digital signals can represent a continuous range of frequencies, while analog signals can only represent a discrete set of frequencies.

Question 25

Classify the signal x[n] = δ(n - 3) + δ(n - 7).

Accepted Answer

Digital, discrete-time, aperiodic

Answer

Analog, discrete-time, periodic

Answer

Digital, discrete-time, periodic

Answer

Analog, discrete-time, aperiodic

Question 26

Which of the following is a defining property of aperiodic signals?

Accepted Answer

They do not repeat themselves after any fixed interval.

Answer

They can be represented as a sum of sinusoidal functions.

Answer

Their duration is always infinite.

Answer

They have a fundamental frequency that defines their repetition rate.

Question 27

Classify the signal x(t) = exp(-t)u(t).

Accepted Answer

Analog, continuous-time, aperiodic

Answer

Analog, continuous-time, periodic

Answer

Digital, continuous-time, aperiodic

Answer

Digital, continuous-time, periodic

Question 28

How does signal classification aid in selecting appropriate signal processing techniques?

Accepted Answer

It identifies signal characteristics, guiding the choice of compatible processing techniques.

Answer

It simplifies algorithms to match input signal characteristics.

Answer

It reduces computational complexity for all input signals.

Answer

It ensures accurate results for all signal types.

Question 29

Determine the steps involved in classifying a signal x(t) as a power signal. Provide the mathematical criterion used for analysis.

Accepted Answer

Calculate the average power of the signal over an infinite interval. If the average power is finite, x(t) is a power signal.

Answer

Examine the signal's energy content and ensure it is infinite.

Answer

Determine the signal's bandwidth and verify that it is infinite.

Question 30

Which of the following signals is continuous-time, periodic, and analog?

Accepted Answer

x(t) = A cos(2πft)

Answer

y[n] = sin(nπ/2)

Answer

w[n] = A δ[n - 1]

Answer

z(t) = e^(-t)

Question 31

Which of the following signals is aperiodic and discrete-time?

Accepted Answer

y[n] = u[n - 3]

Answer

w(t) = e^(-t)

Answer

z(t) = A cos(2πft)

Question 32

Consider the signal x(t) = A sinc(Bt). Which of the following statements is true about x(t)?

Accepted Answer

It is energy-limited and band-limited.

Answer

It is an analog signal but not energy-limited.

Answer

It is periodic but not band-limited.

Question 33

Consider the signal x(t) = e^(-|t|). Which of the following is true about x(t)?

Accepted Answer

It is an analog, continuous-time, and non-periodic signal.

Answer

It is an analog, discrete-time, and non-periodic signal.

Answer

It is a digital, discrete-time, and periodic signal.

Question 34

A signal that is defined for all real values of time is classified as a:

Accepted Answer

Continuous-time signal

Answer

Analog signal

Answer

Digital signal

Answer

Discrete-time signal

Question 35

Which of the following signals is considered periodic?

Accepted Answer

Sinusoidal signal

Answer

Random signal

Answer

Impulse signal

Answer

Unit step signal

Question 36

A signal that takes on a finite number of discrete values is termed as a:

Accepted Answer

Digital signal

Answer

Continuous-time signal

Answer

Analog signal

Answer

Periodic signal

Question 37

Which of the following is an example of a deterministic signal?

Accepted Answer

Periodic signal

Answer

Thermal noise

Answer

Gaussian noise

Answer

Shot noise

Question 38

A signal that is non-zero only within a finite interval is described as a:

Accepted Answer

Finite duration signal

Answer

Infinite duration signal

Answer

Periodic signal

Answer

Exponential signal

Question 39

Which operation among the following is considered non-linear?

Accepted Answer

Saturation

Answer

Differentiation

Answer

Addition

Answer

Multiplication

Question 40

A signal that exhibits both positive and negative values is classified as a:

Accepted Answer

Bipolar signal

Answer

Asymmetrical signal

Answer

Symmetrical signal

Answer

Unipolar signal

Question 41

A signal characterized by its amplitude, frequency, and phase is known as a:

Accepted Answer

Sinusoidal signal

Answer

Unit step signal

Answer

Random signal

Answer

Impulse signal

Question 42

Which of the following signals has a well-defined, repeating pattern?

Accepted Answer

Periodic signal

Answer

Continuous signal

Answer

Analog signal

Answer

Aperiodic signal

Question 43

A signal whose amplitude can take on a continuous range of values is called a(n):

Accepted Answer

Analog signal

Answer

Continuous-time signal

Answer

Digital signal

Answer

Discrete-time signal

Question 44

A signal whose value changes at discrete intervals is referred to as a(n):

Accepted Answer

Discrete-time signal

Answer

Analog signal

Answer

Continuous-time signal

Answer

Periodic signal

Question 45

Which type of signal represents a constant value over an infinite time duration?

Accepted Answer

DC signal

Answer

Transient signal

Answer

Periodic signal

Answer

AC signal

Question 46

A signal that corresponds to real-world physical quantities is known as a(n):

Accepted Answer

Analog signal

Answer

Continuous-time signal

Answer

Discrete-time signal

Answer

Digital signal

Question 47

A signal that repeats its pattern indefinitely is called a(n):

Accepted Answer

Periodic signal

Answer

Continuous signal

Answer

Aperiodic signal

Answer

Transient signal

Question 48

Which of the following is NOT a property used to classify signals?

Accepted Answer

Color

Answer

Amplitude

Answer

Time domain

Answer

Periodicity

Question 49

A signal that is defined at all points in time is called a:

Accepted Answer

Continuous-time signal

Answer

Digital signal

Answer

Discrete-time signal

Answer

Analog signal

Question 50

A signal that repeats itself at regular intervals is called a:

Accepted Answer

Periodic signal

Answer

Discrete signal

Answer

Aperiodic signal

Answer

Continuous signal

Question 51

Signals that have a finite duration are classified as:

Accepted Answer

Aperiodic signals

Answer

Analog signals

Answer

Digital signals

Answer

Periodic signals

Question 52

Which of the following is an example of a continuous-time, aperiodic signal?

Accepted Answer

A Gaussian pulse

Answer

A square wave

Answer

A step function

Answer

A sine wave